DPD Won't Say Why Those Police Cars Are Parked on Every Bridge Along the Tollway ...

An old friend of mine who has better things to do, like get his kid ready for a bar mitzvah tomorrow morning, just called to ask: Why are there Dallas police cars parked on every North Dallas Tollway overpass? He got on at Northwest Highway heading north to Plano, and has seen 'em on every overpass -- all the way to Addison at least.